What the FDA labels say about taking them together
Clarithromycin and diltiazem
Clarithromycin's FDA label of April 9, 2026 names diltiazem in its drug interactions section; the diltiazem labels PlainMeds reads (4) do not name clarithromycin. The clarithromycin label: “These include colchicine toxicity with colchicine; markedly increased transaminases with lomitapide; rhabdomyolysis with simvastatin, lovastatin, and atorvastatin; hypoglycemia and cardiac arrhythmias with disopyramide; …”
Check it at the source: the clarithromycin FDA label on DailyMed (effective April 9, 2026, Solaris Pharma Corporation); the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC).
What does the clarithromycin label say about diltiazem?
Clarithromycin label, drug interactionsAmlodipine Diltiazem Amlodipine, Diltiazem: [See Warnings and Precautions (5.4) ]
Clarithromycin label, warnings and precautionsThese include colchicine toxicity with colchicine; markedly increased transaminases with lomitapide; rhabdomyolysis with simvastatin, lovastatin, and atorvastatin; hypoglycemia and cardiac arrhythmias (e.g., torsades de pointes ) with disopyramide; and hypotension and acute kidney injury with calcium channel blockers metabolized by CYP3A4 (e.g., verapamil, amlodipine, diltiazem, nifedipine).
Source: FDA drug label (Clarithromycin), Solaris Pharma Corporation, effective April 9, 2026 (SPL set 4d42821d-ce7a-7d64-e063-6294a90a0875), via openFDA; the full label on DailyMed
What does the diltiazem label say about clarithromycin?
Diltiazem's label (effective August 7, 2026) and its 3 other brand-application labels do not name clarithromycin in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (TIAZAC EXTENDED RELEASE), Bausch Health US, LLC, effective August 7, 2026 (SPL set c567fe7e-887e-4291-a0d1-2dd3f25cbf25), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Clarithromycin | Diltiazem | |
|---|---|---|
| Labeled for | Bacterial infections, Acid reflux and ulcers | High blood pressure, Angina, Atrial fibrillation |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.466 per tablet 500 mg tablet | $0.144 per capsule 24h ER(cd) 120 mg capsule |
| Shortage now | No current entry | A presentation being discontinued |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once